The invention relates to a display system and method for displaying information relating to data stored on a database.
A typical database stores data defining a variety of field types which changes over time. In the case of personnel records, a set of data fields are maintained for each person including details such as his name, address, grade and the like. From time to time some of this information will change, particularly items such as the person""s grade or address. Currently on the Oracle Human Resources system, this information is stored as one row in the database for each period of information, (for example one row for Jan. 1, 1990 to Feb. 3, 1991 in which the Grade is Grade 1, and one row for Feb. 4, 1991 to Jul. 9, 1991 in which the Grade is Grade 2). More than one piece of information can change at any one time (e.g. a person""s Job Title may change at the same time as their Grade changes), and the changes may apply for different periods of time (e.g. the person""s Grade may change again at a later date without their Job changing again).
When the information is displayed to a user, the information shown is the information that is current as of a particular date, the Effective Date. This Effective Date need not be the current date, but may be changed by the user to display the information that is applicable for any point in time.
One problem with this system is that the user can only see the data for one time period at any one time. They can see the range of dates for which this data is applicable, but not what has changed before and after these dates, and how many other changes have occurred. This was overcome by allowing the user to open up a new window (the Date Track History window) which showed a table with a list of the dates, and the data items which changed on each date. However to see, or alter the data on a particular date, the user had to open a window (the Effective Date window) which allowed them to enter a new Effective Date, and then close the window, refreshing the data in the form.
In accordance with a first aspect of the present invention, a display system for displaying information relating to data stored on a database comprises a processor for obtaining information relating to data stored on a database, the information defining times at which the data changed, and for generating display control signals to cause a display to generate an elongate display element extending along a time axis and which exhibits indicia defining the times of occurrence of changes in the data.
In accordance with a second aspect of the present invention, a method of displaying information relating to data stored in a database comprises obtaining information relating to data stored on the database, the information defining times at which the data changed, and displaying on a display an elongate display element extending along a time axis and which exhibits indicia defining the times of occurrence of changes in the data.
With this invention, a much more user friendly display has been achieved to enable a user to view changes in data stored on a database with changes in data being shown in an easily understandable graphical format without the need to open new windows.
In some cases, however, the elongate display element will only represent a portion of the total time period represented by the data in the database. In order to view other portions of the data, the system is preferably adapted to respond to user input commands to generate a new date with respect to which the elongate display element is redisplayed. Typically, this will be the date on which the elongate display element is centred. In some cases, this could involve entering the date via a keyboard or the like but in a particularly preferred aspect of the invention, the user can utilize the elongate display element itself to define the new date. This is most conveniently achieved using a pointer icon, typically controlled by a mouse.
The indicia defining the times of occurrence of changes in the data could be simple lines but in the preferred approach, the elongate display element is formed of a sequence of sections, each section corresponding to a period during which the data remains unchanged. Typically, adjacent sections will have different colours so that they can be easily distinguished.
In general, the elongate display element will define changes in data of a common field type such as an address or grade in the example mentioned above. However, changes in the data record as a whole or within a group of data items could also be represented. Where changes in multiple data items are shown, these could be represented by a single elongate display element with indicia indicating the change in any of the members of the group or alternatively a set of elongate display elements could be provided one above the other, each corresponding to a single data item.
Typically, date information will be displayed alongside the elongate display element and in some cases the value of the data could be indicated within the elongate display element although often this will be difficult in the limited space usually available.